The present invention relates to an air cleaner element that filters air drawn to, for example, an internal combustion engine.
Conventionally, this type of air cleaner element includes a honeycomb-shaped filter element, as disclosed in, for example, Japanese National Phase Patent Publication No. 2003-514178 (first prior art), Japanese Laid-Open Utility Model Publication No. 2-127766 (second prior art), and Japanese Laid-Open Utility Model Publication No. 2-129231 (third prior art). In the element of these prior arts, an element body is removably mounted in a casing of an air cleaner through a seal member. An air flow is introduced from a first end surface of the element body into the element body. The air flow is then filtered and sent out from a second end surface of the element body.
In the first prior art, a core member is embedded in the center of the element body. A handle is formed at an end of the core member and projects from one of the end surfaces of the element body. To selectively remove and mount the element body, the handle is gripped and the element body is removed from or inserted into the casing of the air cleaner.
In the second prior art, a dust trapping portion is formed in a casing of an air cleaner in such a manner that the dust trapping portion is arranged adjacent to a first end surface of an element body and at an upstream side of an air flow. The dust trapping portion traps large-sized foreign matter such as leaves if the foreign matter enters the casing of the air cleaner. The foreign matter is thus prevented from proceeding toward the first end surface of the element body. This suppresses blockage of the first end surface of the element body by the foreign matter.
In the third prior art, a pre-filter formed by a sponge or a non-woven fabric is secured to a casing of an air cleaner in such a manner that the pre-filter is located adjacent to a first end surface of an element body and at an upstream side of an air flow. The air flow is preliminarily filtered by the pre-filter.
However, the configurations of these prior arts have the following problems. Specifically, in the first prior art, the handle is gripped by the operator when the element body is removed from or secured to the casing. The element body and the core member having the handle must be bonded to each other with high strength in order to resist the friction force based on sealing pressure between the element body and the casing. Accordingly, reinforcement must be provided between the element body and the casing so as to improve the bonding strength. This disadvantageously complicates the manufacture of the element.
Also, in the first prior art, the first end surface of the element body is open to the upstream side of the interior of the casing of the air cleaner without being protected by a guard. As a result, if large sized foreign matter enters the casing, the foreign matter easily reaches the first end surface of the element body and blocks the first end surface. This decreases the amount of air flow that passes through the air cleaner, thus increasing the flow resistance of the air flow and lowering filtering performance of the air cleaner.
Further, in the second and third prior arts, the dust trapping portion or the pre-filter must be incorporated in the casing of the air cleaner. This complicates the configuration of the air cleaner and increases the number of the components. In the third prior art, the pre-filter may be clogged quickly. In this case, as in the first prior art, the flow resistance of the air flow may increase and the filtering performance of the air cleaner drops.